1. Field of the Invention
The present invention relates to a recording apparatus by which an image-receiving paper sheet and an ink sheet are relatively and reciprocatively to conduct image recording with a single color or a plurality of colors, and a set of an image-receiving paper sheet containing a transparent portion in a recording region thereof, which permits viewing an image formed from a backside thereof, and an ink sheet, said set being used in the recording apparatus, and more particularly to a recording apparatus which provides small-sized and cheap recording means capable of recording desired images on both sides of a sheet by one printing operation without need of manual labor or complicated arrangement construction, and a set of an image-receiving paper sheet containing a transparent portion in a recording region thereof, which permits viewing an image formed from a backside thereof, and an ink sheet, said set being used in the recording apparatus.
2. Related Background Art
With the spread of digital video cameras and digital cameras in present, there is a great demand for color printers which record color images obtained thereby. One of the recording systems employed in such color printers is such a method that prescribed portions of an ink sheet coated with a thermally sublimating or melting ink are selectively heated in response to recording information by a thermal head to transfer an ink image to recording paper (image-receiving paper sheet). In particular, a sublimation type thermal transfer-recording apparatus provides a high-quality full-color image and is expected to be a color printer for digital cameras. A melting type thermal transfer-recording apparatus is spread as an apparatus capable of cheaply recording characters or the like.
In a thermal transfer-recording apparatus, a platen roller and a thermal head, in which heating elements to be selectively heated in response to recording information are arranged, are generally provided in opposed relation to each other, an image-receiving paper sheet is relatively and reciprocatively moved with respect to the thermal head on a conveying path of the image-receiving paper sheet and an ink sheet provided between the thermal head and the platen roller in such positional relation that the image-receiving paper sheet and the ink sheet are held between the thermal head and the platen roller, and a prescribed surface of the ink sheet is conveyed to a recording region of the image-receiving paper sheet arranged oppositely to the thermal head, thereby conducting recording of an image. The thermal transfer recording is conducted for every color in the same recording region of the image-receiving paper sheet with an ink layer of plural colors, whereby recording of the plural colors can be conducted. At this time, the positional relation among the platen roller, image-receiving paper sheet, ink sheet and thermal head is such that the image-receiving paper sheet is located on the platen roller, the ink sheet is located on the image-receiving paper sheet, and the thermal head is located on the ink sheet. In this state, the heating elements of the thermal head are selectively heated to sublimate and transfer or melt and transfer inks of corresponding ink sheet portions to a surface portion of the image-receiving paper sheet in contact with the ink sheet, thereby conducting recording of an image on the image-receiving paper sheet. Accordingly, a surface of the image-receiving paper sheet, on which an image can be recorded, is limited to a surface in contact with the ink sheet. Therefore, the surface in contact with the ink sheet had to be changed by some method, for example, by turning the image-receiving paper sheet upside down in order to conduct recording of images on both sides of the image-receiving paper sheet. However, a mechanism of turning the image-receiving paper sheet is required for turning it upside down, and so such problems that the recording apparatus becomes large, and it takes a time to turn the paper upside down have arisen.
In order to solve these problems, Japanese Patent Application Laid-Open No. 10-175375 teaches that a first image is thermally transferred to a transparent film with a single or plural color thermal transfer-recording media, a covering transfer-recording medium is thermally transferred to the support (film) so as to overlap the first image, and a second image is then thermally transferred to the covered portion with a single or plural color thermal transfer-recording media each having a color thermal transfer ink layer.
According to the above-described method, however, it has been necessary to separately align the covering transfer-recording medium with the first image after the formation of the first image though there is no need to turn the image-receiving paper sheet upside down.
The present invention has been made with the foregoing circumstances in view and has as its object the provision of a small-sized and cheap recording apparatus capable of providing desired printed images on both sides of an image-receiving paper sheet to be subjected to double-side printing, and an ink sheet and a recording process used therein.
The above object can be achieved by the following respective aspects of the present invention.
In an aspect of the present invention, there is provided an ink sheet for use in thermal transfer recording comprising a surface for thermal transfer treatment arranged in opposed relation to an image-receiving paper sheet, the surface having a first and second ink layer regions each provided with a thermal transfer type ink layer and a light-shielding-layer-forming region provided with a thermal transfer type light-shielding-layer-forming layer, wherein the first ink layer region is used for thermal transfer to the image-receiving paper sheet before the formation of a light-shielding layer, and the second ink layer region is used for thermal transfer to the image-receiving paper sheet after the formation of the light-shielding layer.
In another aspect of the present invention, there is provided a thermal transfer recording apparatus, comprising arranging means for arranging a surface for thermal transfer treatment of an ink sheet in opposed relation to a recording region of an image-receiving paper sheet, which has a transparent portion that allows viewing an image formed from a backside thereof, and a recording section having heating means, wherein
the surface for thermal transfer treatment of the ink sheet arranged in opposed relation to the image-receiving paper sheet has a first and second ink layer regions each provided with a thermal transfer type ink layer and a light-shielding-layer-forming region provided with a thermal transfer type light-shielding-layer-forming layer, and
the recording apparatus has control means for conducting thermal transfer recording with the first ink layer region, thermally transferring the light-shielding-layer-forming layer from the light-shielding-layer-forming region and then conducting thermal transfer recording with the second ink layer region to the same recording region of the image-receiving paper sheet.
In a further aspect of the present invention, there is provided a thermal transfer recording process for recording an image in a recording region of an image-recording paper sheet by heating a surface for thermal transfer treatment of an ink sheet on the basis of recording information by means of heating means provided in a recording section of a recording apparatus under such a condition that the surface is arranged opposite to the recording region of the image-receiving paper sheet, which has a transparent portion that allows viewing an image formed from a backside thereof, wherein
the surface for thermal transfer treatment of the ink sheet arranged opposite to the image-receiving paper sheet has a first and second ink layer regions each provided with a thermal transfer type ink layer and a light-shielding-layer-forming region provided with a thermal transfer type light-shielding-layer-forming layer,
the process comprising the steps of conducting thermal transfer recording with the first ink layer region, forming a light-shielding layer by thermal transfer of the light-shielding-layer-forming layer and then conducting thermal transfer recording on the light-shielding layer with the second ink layer region to the same recording region of the image-receiving paper sheet.